Truss and connector plates therefor



Feb. 14, 1967 G. M- MCCORMACK 3,304,106

TRUSS AND CONNECTOR PLATES THEREFOR Filed Sept. 30, 1963 2 Sheets-Sheet2 FIG. 8

FIG. I2 70 as o /72 11] :::n A & 74

u:::: u::: o I

[x 41 m::: n::::' & A

INVENTOR.

GERALD M. MCCORMACK BUG/(HORN, BLORE, KLAROU/ST E SPAR/(MAN ATTORNEYSUnited States Patent 3,304,106 TRUSS AND CONNECTOR PLATES THEREFORGerald M. McCormack, Lake Oswego, Oreg., assignor, by

mesne assignments, to Automated Building Components, Inc, Miami, Fla.

Filed Sept. 30, 1963, Ser. No. 312.436 12 Claims. (Cl. 28720.92)

The present invention relates to wood trusses and more particularly to aknockdown type of prefabricated truss and connector plates therefor.

It has become a common practice in the building industry, especially inhouse construction, to employ prefabricated roof trusses rather thanconventional framing. According to present practice the truss membersare cut, assembled on jigs and joined together into a truss by connectorplates pressed into such members at a fabricating plant, and then theassembled trusses are trucked to the job site and incorporated into thestructure. Such prefabricated trusses not only save construction timeand costs by eliminating expensive hand nailing on the job, but also arecapable of withstanding greater loads than conventional roof framing.However, prefabricated trusses are bulky to transport, and usually onlyenough trusses for one or two houses can be shipped in a singletruckload. This has resulted in truss fabricators having to be locatedwithin a relatively few miles of construction sites.

Accordingly, one of the primary objects of the present invention is toprovide a new and improved knockdown type of prefabricated truss whichmay be disassembled for shipment, and then quickly and easily assembledat the job site. A great many more trusses can be transported in asingle truckload when disassembled than when assembled due to thereduction in bulk. Consequently a fabricator can operate economicallythroughout a far greater geographical area if the trusses manufacturedby him can be knocked down for shipment. Moreover, very littleadditional time or handwork is required at the job site to reassemblethe knockdown truss, and such truss maintains the superior strengthcharacteristic of conventional prefabricated trusses.

Another primary object of the present invention is to provide a new andimproved connector plate for assembling 'a knockdown type of truss, suchplate having a plurality of relatively short, integral teeth of lowwithdrawal strength in wood distributed over at least one-half the platesurface and a plurality of longer, integral teeth of high withdrawalstrength in wood provided throughout only the other half of the platesurface. The one-half of the plate with-out long teeth is also providedwith a number of nail holes between the short teeth. Initially the plateis permanently fastened by the long teeth to only one of two abuttingtruss members and removably fastened by the short teeth to the other ofsuch members. The two members may thus be joined at the fabricator,readily separated for shipment with the plate remaining fastened to oneof the two members, and then reassembled permanently on the job inexactly their original relationship simply by driving nails into theother of the members through the holes provided in the plate.

Another object of the invention is to provide a new and improvedconnector plate in which the edges of the elongate teeth are providedwith a series of barbs throughout their length, which barbs extendtoward the plate surface to provide the plate with an exceptionally highresistance to withdrawal from wood.

Another object of the invention is to provide a new and improvedconnector plate having integral teeth, the broad sides of some of whichface in opposite diagonal directions across the plate and the broadsides of others of which face longitudinally of the plate. Accordingly,the teeth resist shear stresses between the plate and a 3,3041% PatentedFeb. 14, 1967 members to which it is fastened regardless of thedirection of such stresses and thereby transmit a balanced load from themember to the plate.

Another object of the present invention is to provide a new and improvedconnector plate having both long and short integral teeth punchedthere-from, the holes left in the plate by the teeth being so spaced andarranged that a multiplicity of bands of plate metal remain, extendingin straight lines laterally, longitudinally and diagonally from edge toedge of the connector plate, thereby providing such plate with a highdegree of rigidity and resistance to distortion regardless of thedirections of the loads imposed on it or stresses induced in it.

A further object of the invention is to provide a new and improvedknockdown joint construction for a structural truss, each joint beingcomposed of two abutting truss members and a pair of the previouslydescribed toothed connector plates joining such members, one on eachside thereof. The long teeth of one plate are embedded initially in oneof the two abutting members only, and the long teeth of the other plateare embedded in the other abutting member only, so that such members mayreadily be separated by applying lateral pressure against the side ofeach member in which no long teeth are embedded.

Still another object of the present invention is to provide a new andimproved method of making a knockdown structural truss. Briefly, themethod includes the steps of first precutting the members to size andshape, then temporarily assembling the truss members using the connectorplate previously described, then disassembling the truss members withthe connector plateson opposite sides of each joint remaining attachedto the opposite ones of the two abutting members of each joint, and thenpermanently reassembling the truss members in their originalrelationship by reinserting the unembedded teeth of each connector platein the original slots made by such teeth and then driving nails throughholes provided in one-half of each plate into the abutting truss member.

Other objects and advantages in addition to the foregoing will becomeobwious upon inspection of the following specification taken inconjunction with the accomp anying drawings wherein like numerals referto like parts throughout, while the features of novelty will be moreparticularly defined in the appended claims.

In the drawings:

FIG. 1 illustrates a side elevational view of a portion of a truss madein accordance with the present invent-ion;

FIG. 2 is a top plan view of a toothed connector plate in accordancewith the present invention;

FIG. 3 is a sectional view taken along the line 3-3 of FIG. 2;

FIG. 4 is a sectional view taken along the line 44 of FIG. 2;

FIG. 5 is an enlarged side elevational view of one of the elongate teethof the connector plate of FIG. 4;

FIG. 6 is a \front elevational view of the tooth of FIG. 5;

FIG. 7 illustrates a modified form of elongate tooth in accordance withthe present invention;

FIG. 8 illustrates a section through a truss joint taken along the line8-8 of FIG. 1;

FIG. 9 is a view similar to FIG. 8 but showing the joint in adisassembled or knockdown condition;

FIG. 10 is a view similar to FIGS. 8 and 9 showing the joint in apermanently assembled state;

FIG. 11 and 12 are top plan views of modified forms of connector platesmade in accordance with the present invention.

Shown in FIG. 1 is a roof truss 10 composed of a plurality of abuttingwooden frame members including two top chord members 11, two bottomchord members 12, 13 and internal chord members 14 and 16, all of whichare joined together at their abutting ends by toothed connector plates18. As shown more clearly in FIG. 8, a typical joint consists of twoabutting frame members 12 and 13 joined together by a pair of connectorplates 18, each of which is fastened to an opposite side of the jointfrom the other by integral teeth embedded in each member. The truss ofFIG. 1 is different from the usual prefabricated roof truss, however, inthat it may be preassembled using the connector plates 18, at afabricating plant, then disassembled for shipment to a constructionsite, and then easily and swiftly reassembled with the same connectorplates and a few hand driven nails in a manner to be more fullydescribed hereinbelow.

As shown in FIG. 2 the connector plate 18 includes a fiat, generallyrectangular metal plate member of generally rectangular shape. The platemay be stamped from a thin sheet of galvanized steel or similarcorrosion resistant metal and is of varying length and width dependingupon the size of truss and particular joint on the truss for which theplate is intended. The plate 18 has a plurality of integral, upstandingshort teeth 24 of triangular shape and longer, narrow teeth or spikes 26struck therefrom which leave a plurality of like-shaped holes 23 in theplate. All of the teeth are bent outwardly from the same side of theplate in a direction substantially normal to the plate surface fromwhich they project as shown more clearly in FIGS. 3 and 4.

The short, triangular teeth 24 are distributed substantially uniformlythroughout the surface area of the plate 18, and the elongate teeth 26are distributed between the triangular teeth 24 over only one-half thesurface area beginning at one edge thereof, or in other words over onlythe portion of the plate that engages one of two abutting frame membersjoined thereby. Nail holes 28 are punched into the other half of theplate between the triangular teeth whereby such half may be permanentlyfastened to one of two abutting frame members in a manner more fullyexplained below. The triangular teeth 24 have a length slightly lessthan the base width thereof and a pair of relatively broad sides 25which when em bedded in wood provide a high resistance to shear stressesinduced between the wood member and the plate. Such teeth 24 also havesmooth, straight edges 27 sloping toward one another and meeting at arelatively blunt point 30. The short length and straight, smooth edgescombine to give such teeth 24 when embedded in wood a characteristic lowresistance to withdrawal from wood, so that a portion of a connectorplate fastened to a memher with only such teeth can easily be disengagedfrom such member.

The elongate teeth 26 have a length L considerably greater than that ofthe short triangular teeth 24, preferably about twice as great, so thatsuch teeth have a considerably greater resistance to withdrawal'fromwood than do the short teeth. As shown most clearly in the enlargedviews of FIGS. and 6, the elongate teeth 26 include a pair of opposededges 34 meeting at a blunt point 36 and a pair of relatively broad,parallel sides 38. The point 36 is deliberately blunted or squared offduring the punching operation to reduce the tendency of the tooth, whenembedded in a wood frame member, to split such member. The thickness Tof the elongate teeth 26 is equal to the thickness of the plate 18.However, the width W is at least twice the thickness T thereof wherebysuch teeth, like the shorter teeth 24, present, in a directionperpendicular to the broad sides 38, a considerable resistance to shearstresses in wood.

With reference now to FIG. 6, both edges 34 of the elongate teeth 26 areundercut at intervals along their lengths to provide a series of barbs40 which extend laterally outwardly of the teeth and toward the plate18. Each barb 40 includes a subedge 42 extending longitudinally of thetooth and parallel to the other subedges on the same edge, and an abruptshoulder 44 extending generally laterally outwardly of the tooth.

The barbs 40 provide the elongate teeth 26 with a substantially greaterresistance to withdrawal from wood than similar but barbless elongateteeth. One advantage of the barbs 40 is that they do not extendlaterally outwardly of the tooth to such an extent as to cut the woodfibers adjacent the barbs as the tooth enters a truss member. Instead,the barbs merely force the wood fibers aside whereby such fibers tend toreturn to their original positions beneath the shoulders 44 of the barbsto enhance the holding power of the elongate teeth;

FIG. 7 illustrates a modified form of elongate tooth or spike 48 made inaccordance with the present invention and having the same length andbarbed edge characteristics as the elongate tooth 26 of FIG. 6. However,the elongate tooth 48 has considerably broader sides 50 than the sidesof the tooth 26, and barbed edges 52 which taper from a broad base to apoint 54. Thus, in addition to having the .same superior resistance towithdrawal as the barbed spike 26, the spike 48 exhibits anexceptionally high resistance to shear in wood in a directionperpendicular to the broad sides 50.

Referring again to FIG. 2, the holes 23 left in the connector plate 18by the triangular and elongate teeth, and the nail holes 28, are spacedand arranged throughout the plate so that a plurality of continuous,straight bands of plate metal remain, as represented by the metalbetween the pairs of dashed lines 53 of FIG. 2. A plurality of suchbands extend uninterruptedly laterally, longitudinally and in bothdiagonal directions with respect to the plate 18, from edge to edgethereof between such holes. These bands of metal provide the plate witha unique rigidity and resistance to distortion in all directions of theplate despite the large number of holes punched therein. Some connectorplates being manufactured today are provided with as many teeth aspossible within the available plate surface area so as to provide theplate with a high gripping strength and resistance to shear in thestructural member. However, a factor sometimes overlooked is that theflat plate member itself must have considerable strength and rigidity inorder to form a rigid joint and withstand, without distortion, the highstresses induced in it in all directions by the loads imposed by theabutting truss members. Accordingly, by providing the bands 58 of metalin all directions in the plate, a high plate strength is retained whileproviding an adequate number and arrangement of teeth to provide highgripping strength and resistance to shear in the truss members.

The short teeth 24 of the connector plate 18 are arranged in straightrows extending in both diagonal directions across the plate. The broadsides 25 of all of the short teeth in on diagonal row extend in the samediagonal direction, and the broad sides of the short teeth in adajacent,parallel rows face in opposite diagonal directions, so that about halfthe total number of short teeth in any portion of the plate face in eachof the two diagonal directions. The elongate teeth 26, on the otherhand, are arranged in longitudinally extending straight rows, and withthe broad sides 38 of such teeth facing longitudinally of the plate.Thus, the broad sides of substantial number of teeth in each pair ofplates joining two truss members resist shear forces between the membersand the plates which tends to slide the plates relative to such members,regardless of the direction and location of such shear forces withrespect to the plates. The uniform distribution of teeth in suchdirections results in a balanced load being transmitted through theteeth to all portions of the plates at any joint.

FIGS. 8, 9 and 10 illustrate the preassembly, disassembly, and finalassembly of a typical knockdown truss joint using a pair of connectorplates 18. Each joint is composed of a pair of abutting frame members 12and 13, which for purposes of illustration are chord members of thetruss of FIG. 1, and a pair of identical connector plates 18 and 18a,one being on each of the op posite sides of the joint. In the initialassembly of the joint at the fabricator, both plates are applied to thejoint simultaneously, by means of a large mechanical press, with theelongate teeth 26 of the plate 18 being pressed into one side of oneframe member 12 at the time that the elongate teeth 26 of the otherconnector plate 18a are pressed into the opposite side of the otherframe member 13.

Then following initial assembly, as shown in FIG. 9, the joint is easilydisassembled by applying lateral force in opposite directions toopposite sides of the two members 12 and 13, the lateral force beingapplied at the joint to the side of each member in which no elongateteeth are embedded. Since the short teeth 24 have very little withdrawalstrength, the joint is easily disassembled using a hammer to rap theappropriate side of one of the frame members while the other issupported laterally to resist the hammer blow. Each plate 18, 18a, willremain fastened, however, to the member in which the elongate teeth 26of each are embedded.

It has been found in practice that a sh-ort triangular tooth 24 having alength of about five sixteenths of an inch is preferred to provideadequate shear strength but low enough withdrawal strength to permiteasy disassembly of a joint. On the other hand, a short tooth 24 morethan three eighths of an inch in length will make disassembly difficult.The elongate teeth 26 should be no less than one-half an inch in lengthor about eight times the plate thickness to provide adequate withdrawalstrength, while it is preferred to use an elongate tooth of the order offive eighths of an inch.

As shown in FIG. 10, final, permanent assembly of the joint between themembers 12 and 13 is accomplished easily by realigning such members intheir original positions with respect to one another and reinserting theshort teeth of the free half of each plate into the slots in the membersleft by such teeth upon disassembly of the joint. Then, the abuttingmembers 12 and 13 are permanently fastened together by driving nails 60by hand through the holes 28 in the free half of each plate and into theframe members 12 and 13. A relatively few hand driven nails need be usedto effect a permanent joint compared with the number of such nails thatwould be necessary should there be no integral elongate teeth 26 or ifthe truss were assembled entirely at the construction site using handdriven nails.

With reference again to FIG. 1, the truss is composed of a plurality offrame members the abutting ends of which form joints similar to the onedescribed in detail with reference to FIGS. 8 through 10. In order toeasily assemble and disassemble the truss, it is recommended that theconnector plates at both ends of each truss member be assembled in therelationship shown with respect to the abutting truss member. That is,the two connector plates on one side at either end of each internalchord member 14, 16 both have their elongate teeth embedded in theinternal member, while on the other side of such internal members thelong teeth 26 of each connector plate are embedded in the respectiveabutting external chord members 10 and 12. In a similar fashion, theelongate teeth of the two connector plates at opposite ends of one sideof the lower chord member 12 are embedded in the abutting external framemembers 10 and 13, whereas the elongate teeth of the connector plates onthe opposite side of the member 12, are embedded in such member 12.

In knocking down the truss, the internal members .14 and 16 are removedfirst, merely by striking each member 14, 16 on the side thereofopposite the sides shown, or in other Words, on the side in which noelongate teeth are embedded. Then after the internal members 14 and 16are removed from the truss, the frame member 12 may 6 be removed byapplying force against the side there-of shown. The remaining externalmembers may then be separated easily in a similar manner. Final assemblyof the truss can best be performed by fastening the individual memberstogether in reverse order from disassembly, with the internal membersbeing added lastly.

While several of the features of the invention have been described withrespect to a connector plate 18 adapted for use in constructing aknockdown truss, these features may likewise be embodied in a connectorplate for assembling a conventional prefabricated truss in which aconstant tooth pattern exists throughout the entire surface area of theplate.

Accordingly, as shown in FIG. 11, a connector plate 62 is provided witha plurality of triangular teeth 64 and integral elongate teeth 66 havingthe ame configurations as the teeth 24 and 26 respectively of plate 18but with the elongate teeth 66 being distributed throughout the entireplate surface area rather than over only one-half thereof.

The teeth of the plate 62 are also spaced and arranged in the samepattern as are the teeth of plate 18 so as to transmit a balanced loadto the plate and to provide the plate diagonally, longitudinally andlaterally extending bands of metal from edge to edge thereof for platestrength. The plate 62 requires no nail holes, of course, inasmuch asthe elongate teeth 66 are provided throughout the plate, therebyeliminating the necessity for the use of hand driven nails.

FIG. 12 illustrates another modification of a connector plate 68 havingonly barbed elongate teeth 70 over onehalf the plate surface and onlyshort, triangular teeth and nail holes 74 over the other half of suchsurface. Thus the plate 68 is also of the knockdown type and may be usedto assemble the truss of FIG. 1.

While the invention has been described with reference to certainillustrated embodiments, it is to be understood that such embodimentsand the description thereof is illustrative only and that variousmodifications in arrangement and detail will occur to those having skillin the art. I claim as my invention all such modifications as comewithin the true spirit and scope of the following claims.

I claim:

1. A toothed connector plate for fastening together and transmittingloads between abutting structural wooden members, said plate comprising:

(a) a flat, :metal plate member,

(b) a plurality of integral, spaced apart fastening means extendingunidirectionally from and in a direction substantially normal to saidplate member for im-bedding into said abutting members,

(c) said fastening means including a plurality of relatively short toothmeans having broad sides and straight edges so as to have a highresistance to shear in wood and a low resistance to withdrawaltherefrom,

(d) said short tooth means being distributed substantially uniformlythroughout at least one-half the surface area of said plate member,

(e) others of said fastening means including a plurality of elongatetooth means of considerably greater length than said short tooth meansso as to have a higher resistance to withdrawal from wood,

(f) said elongate tooth means being distributed throughout at least theother half of said surface area of said plate member,

(g) said elongate tooth means being distributed over only about one-halfthe surface area of said plate member, beginning at one end thereof, sothat said elongate teeth become embedded in only one of two abuttingwood members joined by said plate member, the other half of said platemember having nail holes punched therein at intervals between said shorttooth means.

2. A toothed connector plate for fastening together and transmittingloads between abutting structural wooden members, said plate comprising:

(a) a flat, metal plate member,

(b) a plurality of integral, spaced apart fastening means extendingunidirectionally from and in a direction substantially normal to saidplate member for embedding into said abutting members,

() said fastening means including a plurality of relatively short toothmeans having broad sides and straight edges so as to have a highresistance to shear in wood but a low resistance to withdrawal therefrom,

(d) said short tooth means being distributed substantially uniformlythroughout at least one-half the surface area of said plate member,

(e) others of said fastening means including a plurality of elongatetooth means of considerably greater length than said short tooth meansso as to have a higher resistance to withdrawal from wood,

(f) said elongate tooth means being distributed throughout at least theother half of said surface area of said plate member,

(g) said elongate tooth means being provided with a pair of opposed,relatively broad sides having a width at least twice the thicknessthereof, said broad sides of said elongate tooth means facing in adirection longitudinally of said plate member and aid broad sides ofsaid short tooth means facing diagonally across said plate.

3. A toothed connector plate for fastening together and transmittingloads between abutting structural wooden members, said plate comprising:

(a) a flat, metal plate member,

(b) a plurality of integral, spaced apart fastening means extendingunidirectionally from and in a direction substantially normal to saidplate member for embedding into said abutting members,

(c) said fastening means including a plurality of relatively short toothmeans having broad sides and straight edges so as to have a highresistance to hear in wood but a low resistance to withdrawal therefrom,

(d) said short tooth means being distributed substantially uniformlythroughout at least one-half the surface area of said plate member,

(e) others of said fastening means including a plurality of elongatetooth means of considerably greater length than said short tooth meansso as to have a higher resistance to withdrawal from wood,

(f) said elongate tooth means being distributed throughout at least theother half of said surface area of said plate member,

(g) said short and elongate tooth means being arranged on said .platesurface so that a plurality of bands of plate metal extend in a straightline between the holes left by said tooth means in said plate indirections laterally, longitudinally and diagonally from edge to edge ofsaid plate member.

4. A toothed connector plate for fastening together and transmittingloads between abutting structural wood members, said plate comprising:

(a) a flat, metal plate member,

(b) a plurality of integral, spaced apart fastening means extendingunidirectionally from and in a direction substantially normal to saidplate member for embed-ding into said abutting members,

(c) said fastening means including a plurality of relatively short toothmeans having broad sides and straight edges so as to have a highresistance to shear in wood but a low resistance to withdrawaltherefrom,

(d) said short tooth means being distributed substantially uniformlythroughout at least one-half the surface area of said plate member,

(e) others of said fastening means including a plurality of elongatetooth means of considerably greater length than said short tooth meansso as to have a higher resistance to withdrawal from wood,

(f) said elongate tooth means being distributed throughout at least theother half of said surface area of said plate member,

(g) both edges of each said elongate tooth means being provided with aplurality of barbs along substantially the entire length of said edges,each of said barbs including an edge portion extending generallylongitudinally of said tooth means and an abrupt shoulder extendinggenerally laterally outwardly of said tooth means.

5. A toothed connector plate for fastening together and transmittingloads between abutting frame members of a wooden structure, saidconnector plate comprising,

(a) a thin metal plate member,

(b) a plurality of short integral teeth bent outwardly in a directionsubstantially normal to said plate member,

(c) said short teeth having a length no greater than three eighths of aninch,

(d) said short teeth being distributed substantially uniformlythroughout at least onehalf the surface area of said plate beginning atone edge thereof,

(e) a plurality of integral elongate teeth bent outwardly from saidplate member in the same direction as said short teeth,

(f) said elongate teeth having a length no less than one-halfinch,

(g) said elongate teeth being distributed over no more than the otherhalf the surface area of said plate beginning at an edge opposite saidone edge,

(h) and said plate having a plurality of nail holes punched thereinbetween said short teeth over only said one-half said surface area.

6. A toothed connector plate for fastening together and transmittingloads between two or more adjoining wood structural frame members, saidconnector plate comprising:

(a) a thin metal plate member,

(b) a plurality of teeth struck from said plate member and projectingunidirectionally therefrom,

(c) some of said teeth being relatively short and triangular and theothers of said teeth being elongate and narrow,

(d) the elongate teeth being at least about twice as long as thetriangular teeth,

(e) both said elongate teeth and said triangular teeth having relativelynarrow edges equal in thickness to that of said plate and relativelybroad sides of greater width than the thickness of said edges,

(f) said triangular teeth being distributed substantially uiiiformlythroughout the entire surface area of said p a-te,

(g) said elongate teeth being interspersed between said triangularteeth, throughout at least one-half the surface area of said plate,

(h) the broad sides of said triangular teeth facing diagonally acrosssaid plate, with alternate ones of said triangular teeth longitudinallyof said plate extending in one diagonal direction and adjacent ones ofsaid triangular teeth extending in opposite diagonal directions,

(i) the broad sides of said elongate teeth facing longitudinally of saidplate.

7. A toothed connector plate for fastening together and transmittingloads between two or more abutting wood structural frame members, saidconnector plate comprising:

(a) a thin metal plate member,

(b) a plurality of short teeth struck from said plate member to leavelike shaped holes in said member, said short teeth being distributedsubstantially uni- 9 formly throughout the surface area of said platemember,

() a plurality of elongate teeth having a length subtially greater thanthat of said triangular teeth struck from said plate to leave likeshaped holes in said plate member,

(d) said elongate teeth being distributed over at least one-half thesurface area of said plate between said short teeth,

(e) the holes in said plate member left by said teeth being spaced andarranged so that in each of the lateral, longitudinal and both diagonaldirections of said plate a plurality of continuous bands of plate metalextend in a straight line from edge to edge thereof and between saidholes to provide said plate with rigidity and resistance to distortion.

8. A connector plate according to claim 7 wherein said elongate teethare provided throughout substantially no more than one-half the surfacearea of said plate beginning from one edge thereof, the other one-halfsaid plate area having nail holes punched therein between saidtriangular teeth, said nail holes being so spaced and arranged over saidplate that said continuous bands of plate metal extend uninterruptedlyin said other one-half said plate surface area from edge to edge of saidplate.

9. A prefabricated structural joint for transmitting loads and havingthe capacity to be disassembled after initial assembly, said jointcomprising:

(a) a pair of abutting wooden members,

(b) a pair of connector plates, one engaging each side of said abuttingmembers and'spanning the joint there'between,

(c) said plates having a plurality of pointed teeth struck therefrom andembedded in said abutting members,

((1) said teeth including relatively short, broad ones having lowwithdrawal strength and high shear strength distributed substantiallyuniformly over at least one-half the surface areas of said plates,

(e) the remainder of said teeth being elongate and substantially longerthan said short teeth to provide a higher withdrawal strength anddistributed over no more than the other half the surface areas of saidplates,

(f) the elongate teeth of one of said plates being embedded in one ofsaid members only,

(g) said elongate teeth of the other of said plate being embedded in theother of said members only,

(h) so that lateral pressure applied to the side of each of said membersin which no elongate teeth are embedded will cause said members toseparate with said one plate remaining fastened to said one member andsaid other plate remaining fastened to said other member,

(i) said plates also having nail holes punched therein between saidtriangular teeth over said onehalf of each plate,

(j) so that said one-half of each said plates may be permanentlyfastened to the respective abutting member with which said one-half ofeach plate engages by driving nails through said holes and into oppositesides of said abutting members.

10. A prefabricated, knockdown truss structure composed of a pluralityof abutting wooden frame members;

(a) each of said frame members being joined at both ends to an abuttingframe member by a pair of toothed connector plates, one on each side ofsaid member at each end thereof,

(b) about one-half the surface area of each plate engaging each of twoabutting frame members,

(c) each of said plates having a plurailty of short, integral teethformed so as to have a high resistance to shear stresses in Wood and alow resistance to withdrawal from wood,

(d) said short teeth being distributed substantially uniformlythroughout the entire surface areas of said plates and embedded in bothsaid abuting frame members,

(e) each of said plates also having a plurality of elongate integralteeth formed so as to have a higher resistance to withdrawal from woodthan said short teeth and distributed between said short teeththroughout substantially one-half the surface area of each said plate,

(f) said elongate teeth of each said plate being embedded in only one ofsaid two abutting frame members,

(g) the other one-half the surface area of each plate being providedwith a series of nail holes between said short teeth for permanentlyfastening said plate to the other of said abutting frame members,

(h) said elongate teeth of one of said pair of connector plates at eachend of each frame member being embedded in one of said two abuttingmembers and said elongate teeth of the other of said pair of connectorplates being embedded in the other of said two abutting members,

(i) so that the abutting frame members of said truss may be disassembledby the application of force at each end of each frame member laterallyagainst the side of each said member in which there is an absence ofelongate teeth, and subsequently reassembled by driving nails into oneside only of each member at each joint through the nail holes providedin said plates.

11. A truss according to claim 10 wherein the elongate teeth of each ofthe two connector plates joining the internal frame members of saidtruss to the external frame members thereof on one side of said internalmember are embedded in said internal frame member and the elongate teethof the connector plates on the other side at each end of each saidinternal frame member are embedded in the abutting external framemembers.

12. The method of making a structural truss composed of a plurality ofabutting wooden frame members connected together by a pair of toothedmetal connector plates at each joint, said connector plates each havingshort teeth over at least one-half the plate surface area, longer teethover the other half only of the plate surface area and nail holesbetween the short teeth over said onehalf the plate area, said methodconsisting of the following steps:

(a) precutting the frame members to size and shape,

(b) arranging said precut frame members in their correct abuttingrelationship with respect to one another;

(c) fastening together the abutting frame members with said connectorplates, one on each side of each joint, by embedding the long teeth ofone connector plate at each joint in one of the abutting members and byembedding the long teeth of the other connector plate at each joint inthe other of the abutting members, while simultaneously embedding theshort teeth of each plate in said abutting members,

(d) then disassembling said abutting frame members by applying lateralpressure to the side of each frame member at each joint in which noelongate teeth are embedded, said lateral pressure being sufficient tocause the two abutting frame members at each joint to separatelaterally, with one connector plate remaining attached to said oneabutting frame member and said other connector plate remaining attachedto said other abutting frame member,

(e) then permanently assembling said abutting frame members in the sameabutting relationship with respect to one another at each joint as inthe original assembly thereof, by first reinserting the previously 1 1 11 2 embedded but now unem'bedded short teeth of said References Cited bythe Examiner one connector plate at each joint into the respectiveUNITED STATES PATENTS slot made by such short teeth in said otherabuttin p 705,626 7/1902 Vogel 20-92 frame member, and doing the samewith respect to 29371418 5/1960 Sanford 2O 92 the now unembedded shortteeth of said other con- 5 nector plate, and then driving nails into theside of HARRISON MOSELEY, Primary Examiner each frame member at eachjoint in which no elongate teeth are embedded through the nail holespro- REINALDO MACHADO Examine vided in said connector plates. A. I.BREIER, Assistant Examiner.

1. A TOOTHED CONNECTOR PLATE FOR FASTENING TOGETHER AND TRANSMITTINGLOADS BETWEEN ABUTTING STRUCTURAL WOODEN MEMBERS, SAID PLATE COMPRISING:(A) A FLAT, METAL PLATE MEMBER, (B) A PLURALITY OF INTEGRAL, SPACEDAPART FASTENING MEANS EXTENDING UNIDIRECTIONALLY FROM AND IN A DIRECTIONSUBSTANTIALLY NORMAL TO SAID PLATE MEMBER FOR IMBEDDING INTO SAIDABUTTING MEMBERS, (C) SAID FASTENING MEANS INCLUDING A PLURALITY OFRELATIVELY SHORT TOOTH MEANS HAVING BROAD SIDES AND STRAIGHT EDGES SO ASTO HAVE A HIGH RESISTANCE TO SHEAR IN WOOD AND A LOW RESISTANCE TOWITHDRAWAL THEREFROM, (D) SAID SHORT TOOTH MEANS BEING DISTRIBUTEDSUBSTANTIALLY UNIFORMLY THROUGHOUT AT LEAST ONE-HALF THE SURFACE AREA OFSAID PLATE MEMBER, (E) OTHERS OF SAID FASTENING MEANS INCLUDING APLURALITY OF ELONGATE TOOTH MEANS OF CONSIDERABLY GREATER LENGTH THANSAID SHORT TOOTH MEANS SO AS TO HAVE A HIGHER RESISTANCE TO WITHDRAWALFROM WOOD, (F) SAID ELONGATE TOOTH MEANS BEING DISTRIBUTED THROUGHOUT ATLEAST THE OTHER HALF OF SAID SURFACE AREA OF SAID PLATE MEMBER, (G) SAIDELONGATE TOOTH MEANS BEING DISTRIBUTED OVER ONLY ABOUT ONE-HALF THESURFACE AREA OF SAID PLATE MEMBER, BEGINNING AT ONE END THEREOF, SO THATSAID ELONGATE TEETH BECOME EMBEDDED IN ONLY ONE OF TWO ABUTTING WOODMEMBERS JOINED BY SAID PLATE MEMBER, THE OTHER HALF OF SAID PLATE MEMBERHAVING NAIL HOLES PUNCHED THEREIN AT INTERVALS BETWEEN SAID SHORT TOOTHMEANS.